Aether and Gravitation

by William George Hooper

Thus from philosophical considerations we affirm that each star, while it is itself the centre of a starry system, is also dependent upon and associated with some other body, to which it is held bound by the electro-magnetic Aether, and around which it is made to revolve by the circulating electro-magnetic currents associated with that central body. So that by philosophical reasoning we are led to view the whole of the innumerable stars that flood interstellar space, not as so many individual and isolated units, that have no relation to each other, but rather as parts of one great system, which in its entirety may form in its ultimate unity one harmonious whole, a universe.

As we come to consider star clusters and nebulae, we shall see how this idea of unity seems to be manifested throughout all celestial phenomena.

Art. 119. Aether and Nebulae.--In addition to the host of stars that flood the infinite space, there are other celestial bodies that meet the gaze of the astronomer as the telescope is turned upon the heavens.

These bodies, which are glowing masses of gaseous matter, are termed Nebulae. The word Nebulae signifies a cloud, but they are not clouds in the same sense as we apply that term to masses of vapour that exist in our own atmosphere. Sir Wm. Herschel did more towards the discovery of nebulae than perhaps any other astronomer, either before his time or since. His labours in the direction were completed and enlarged by his son, Sir John Herschel, who surveyed the Southern heavens in a way that had never been accomplished before.

The result of the combined labours of the two Herschels has placed information of the nebulae at our disposal which is invaluable. Several thousands of different nebulae are now known to us, and as the telescope is improved and its powers increased, fresh nebulae are being added to the number. Like stars, nebulae vary not only in size, but also in colour, shape, and even in the materials of which they are composed. They also vary in brightness, the light from some being much fainter than the light from others.

It has been estimated by Huggins that the light received from a nebula will not exceed the light of a sperm candle looked at from a distance of a quarter of a mile. It is thought by some astronomers that the light received from a nebula is indicative of the stage of development to which it has arrived. Where the light is faint, the nebulae are in their first stages of formation, and where it is brighter it is indicative of a more advanced stage of development. Thus nebulae may consist of nebulous matter in various stages of condensation, but they are not yet in that condition which corresponds to the condition supposed to exist in our sun.

Nearly all the nebulae lie outside the Milky Way, so that it would seem as if in ages past all the nebulae that had ever existed in this starry zone had passed out of their nebulous condition and been further condensed into suns or stars, as they are called. Astronomical observations teach us that there are very few nebulae indeed to be seen in this starry highway, the part of the heavens which are richest in them lying far beyond the confines of this zone. For many years certain aggregations of luminous points in the heavens were supposed to be nebulae, but by the aid of more powerful telescopes they have now been resolved into clusters of stars. One of these clusters is the cluster in Hercules, while another is the great nebula of Orion. In the case of the former, situated in the constellation of Hercules, we find a great number of very small points of light grouped together in a more or less globular form. When looked at through a small telescope, this object looks like a nebula, but looked at through Lord Rosse's, or some other great telescope, it becomes at once resolved into an immense number of separate points of light, each one representing a star, there being between one and two thousand altogether in this constellation.

Clusters of stars are usually globular in form, though some are irregular in outline. The latter are generally rich in stars, with a less condensation of stars towards the centre. Sir Wm. Herschel considered the irregular clusters as being in a less advanced stage of condensation, as he was of the opinion that all groups ultimately tended to clusters which were globular in form. Before dealing with the different kinds of true nebulae we will now consider the question as to “What are Nebulae?”

Art. 120. What are Nebulae?--The question which presents itself to the mind of all astronomers when they have viewed the wondrous nebulae that exist in far-off space is, “What are Nebulae?” This question is so closely identified with the question as to “What is Matter?” that the solution of the one will give us the key to the solution of the other. It is now generally admitted, that nebulae are composed of a glowing mass of gaseous matter, that gaseous matter being partly composed of the gas Hydrogen. Dr. Huggins in 1864 first made the discovery of the existence of Hydrogen in certain nebulae by means of the spectroscope, which distinctly revealed certain lines that proved the existence of Hydrogen in the nebulae.

In the spectra of some of the nebulae, that of 31 Andromeda, for example, there are no dark lines shown, but only a continuous band of bright light, which would seem to indicate that there was no glowing gaseous matter in that nebula at all. But accepting the fact that the nebulae are composed of glowing gaseous matter, the problem confronts us as to where this gaseous matter comes from.